This invention relates to digital television receivers, and more particularly, to a method and apparatus for providing a digital television receiver which is fundamentally capable of demodulating and demultiplexing digital TV signals from a plurality of physically independent channels.
Digital television broadcasts are well known in the art. Common digital video service networks which provide digital television broadcasts to user""s include digital cable TV, digital satellite TV, video-on-demand, and terrestrial digital TV broadcasting systems. In each of these services a service operator broadcasts information to a multitude of end users in the form of digital television signals provided over a specific transmission channel.
For example, in digital satellite television broadcasting a service operator transmits its signal over a satellite channel, i.e., from a transmission antenna to a satellite, and then from the satellite to a satellite dish antenna at a user""s home. The signal is then fed from the satellite dish antenna to a receiver for demodulation and demultiplexing so that the user may use the received signal.
In another example, digital cable television broadcasts are transmitted by a service operator over a hardwired cable network directly into the user""s home. That transmission channel, the digital television cable, is hardwired directly into the user""s receiver for demodulation and demultiplexing, so that the user may use the received signal.
In each of these examples, the receiver obtains the signal from a specific transmission channel. However, oftentimes users desire to receive their digital television signals from multiple transmission channels.
Currently, the art does not provide for this functionality. If a user desires multiple transmission channel inputs, then the user must have a receiver to communicate with each respective, independent transmission channel. Each receiver is configured to demodulate and demultiplex the specific signal from the respective transmission channel and then send the end signal to the television for viewing.
This requirement for multiple receivers to communicate with multiple transmission channels is wasteful, costly and redundant. Requiring the user to obtain multiple receivers also provides an artificial block to competition in television broadcasting. Once a user obtains hardware in conjunction with a specific service, they will be less likely to switch to another service if they are displeased with that original service due to the additional requirement that they also obtain new hardware.
Thus, there is a need to eliminate this redundancy and provide a system which allows users to access multiple broadcast transmission channels, whether that access is to the multiple channels at the same time or in seriatim. There is a further need to minimize the cost for users to access multiple transmission channels and to provide users with increased choices for receiving information.
Digital television signals are generally broadcast in the MPEG-2 format. MPEG-2 is a well known standard which was adopted on Nov. 4, 1994 by the ISO (International Organization for Standards) Motion Picture Experts Group (MPEG) for audio/video digital signal compression, configuration and transmission. The MPEG-2 Standard allows for consistent and uniform digital video signal sampling, coding, transmission and reception throughout the world and is very well known in the art.
Through the known systems designed according to the MPEG-2 Standard (which is also known as International Standard ISO/IEC 13818-1), the packetizing, multiplexing, and sending of coded bit streams of multiple programs may be accomplished. Using this standard signal configuration, multiple programs, along with audio and video overlays may be transmitted by a service operator and received by an end user over a specific transmission channel. Details of MPEG-2 Systems can be also found in the textbook, Digital Video: An Introduction to MPEG-2, Barry G. Haskell and et. al., Champman and Hall, New York, N.Y., USA, 1997.
Since the adoption of the MPEG-2 Standard, service networks have proliferated around the world which networks provide digital television programming to end users. Each of these digital television broadcast services provide an MPEG-2 signal to end users over one of the transmission channels discussed above.
Therefore, it is an object of the present invention to provide methods and apparatus for digital television reception which allow users to receive their digital television signals from multiple transmission channels.
It is yet another object of the present invention to provide methods and apparatus for digital television reception which allow users to eliminate the redundancy of multiple receivers to simultaneously access multiple independent transmission channels.
It is yet still another object of the present invention to provide methods and apparatus for digital television reception which allow users to reduce the cost of digital television reception.
These, together with other objects of the present invention, along with the various features of novelty which characterize the present invention, are pointed out with particularity in the claims annexed to and forming a part of this disclosure.
The above and other objects are achieved by the present invention, which provides methods and apparatus for receiving digital television signals where the receiver is capable of demodulating and demultiplexing the digital television signals from multiple, independent transmission channels.
The preferred embodiment of the present invention provides for a Dual Channel Digital TV Receiver which receives signals from two independent transmission channels. However, the present invention should not be limited to the preferred embodiment and may be applied to any number of independent transmission channels by extrapolating the principles shown within the preferred Dual Channel Digital TV Receiver.
In order to address each of the digital television signals from the two independent transmission channels, the Dual Channel Digital TV Receiver of the preferred embodiment of the present invention includes two independent paths for channel demodulation and transport stream demultiplexing. Thus, within the Dual Channel Digital TV Receiver of the preferred embodiment of the present invention, signals from each of the transmission channels are received, decoded and sent for further processing or viewing, as desired by the user.
By providing this dual channel signal processing capability, the Dual Channel Digital TV Receiver of the preferred embodiment of the present invention allows for versatile program viewing capabilities, including but not limited to, allowing the user to view a program from any one of the transmission channels being accessed, allowing for the recording of programs from one or multiple transmission channels to a digital storage device (which digital storage device may be a part of the Dual Channel Digital TV Receiver), allowing the user to view a program from one transmission channel while recording programs from one or more transmission channels, replaying previously recorded programs, and replaying previously recorded programs while recording programs of one or more transmission channels.
The preferred receiver for a digital video service network which embodies the present invention comprises: a first means for receiving a first digital television signal from a first transmission channel; a second means for receiving a second digital television signal from a second transmission channel; a means for decoding at least the first digital television signal or the second digital television signal; and a means for providing an output signal reflective of a television program contained within either the first digital television signal or the second digital television signal.
The preferred method for receiving digital television signals used by the preferred embodiment of the present invention, comprises the steps of: receiving a first digital television signal from a first transmission channel; receiving a second digital television signal from a second transmission channel; decoding the first digital television signal; decoding the second digital television signal; and providing an output signal reflective of a television program contained within either the first digital television signal or the second digital television signal.